'\" te
.\" Copyright (c) 2004, Sun Microsystems, Inc.
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.TH GETINFO 9E "Jan 16, 2008"
.SH NAME
getinfo \- get device driver information
.SH SYNOPSIS
.nf
#include <sys/ddi.h>
#include <sys/sunddi.h>



\fBint prefix\fR\fBgetinfo\fR(\fBdev_info_t *\fR\fIdip\fR, \fBddi_info_cmd_t\fR \fIcmd\fR,
     \fBvoid *\fR\fIarg\fR, \fBvoid **\fR\fIresultp\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI). This entry point is \fBrequired\fR for
drivers which export \fBcb_ops\fR(9S) entry points.
.SH ARGUMENTS
.ne 2
.na
\fB\fIdip\fR\fR
.ad
.RS 11n
Do not use.
.RE

.sp
.ne 2
.na
\fB\fIcmd\fR\fR
.ad
.RS 11n
Command argument - valid command values are \fBDDI_INFO_DEVT2DEVINFO\fR and
\fBDDI_INFO_DEVT2INSTANCE\fR.
.RE

.sp
.ne 2
.na
\fB\fIarg\fR\fR
.ad
.RS 11n
Command specific argument.
.RE

.sp
.ne 2
.na
\fB\fIresultp\fR\fR
.ad
.RS 11n
Pointer to where the requested information is stored.
.RE

.SH DESCRIPTION
When \fIcmd\fR is set to \fBDDI_INFO_DEVT2DEVINFO\fR, \fBgetinfo()\fR should
return the \fBdev_info_t\fR pointer associated with the \fBdev_t\fR \fIarg\fR.
The \fBdev_info_t\fR pointer should be returned in the field pointed to by
\fIresultp\fR.
.sp
.LP
When \fIcmd\fR is set to \fBDDI_INFO_DEVT2INSTANCE\fR, \fBgetinfo()\fR should
return the instance number associated with the \fBdev_t\fR \fIarg\fR. The
instance number should be returned in the field pointed to by \fIresultp\fR.
.sp
.LP
Drivers which do not export \fBcb_ops\fR(9S) entry points are not required to
provide a \fBgetinfo()\fR entry point, and may use \fBnodev\fR(9F) in the
\fBdevo_getinfo\fR field of the \fBdev_ops\fR(9S) structure. A \fBSCSI HBA
\fRdriver is an example of a driver which is not required to provide
\fBcb_ops\fR(9S) entry points.
.SH RETURN VALUES
\fBgetinfo()\fR should return:
.sp
.ne 2
.na
\fB\fBDDI_SUCCESS\fR\fR
.ad
.RS 15n
on success.
.RE

.sp
.ne 2
.na
\fB\fBDDI_FAILURE\fR\fR
.ad
.RS 15n
on failure.
.RE

.SH EXAMPLES
\fBExample 1 \fR\fBgetinfo()\fR implementation
.sp
.in +2
.nf
/*ARGSUSED*/
static int
rd_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
    void **resultp)
{
     /*
      * Note that in this simple example
      * the minor number is the instance
      * number.
      */

     devstate_t *sp;
     int error = DDI_FAILURE;
     switch (infocmd) {
     case DDI_INFO_DEVT2DEVINFO:
	  if ((sp = ddi_get_soft_state(statep,
	      getminor((dev_t) arg))) != NULL) {
		 *resultp = sp->devi;
		 error = DDI_SUCCESS;
	  } else
		 *result = NULL;
	  break;

     case DDI_INFO_DEVT2INSTANCE:
	  *resultp = (void *) (uintptr_t) getminor((dev_t) arg);
	  error = DDI_SUCCESS;
	  break;
     }

     return (error);
}
.fi
.in -2

.SH SEE ALSO
.BR ddi_no_info (9F),
.BR nodev (9F),
.BR cb_ops (9S),
.BR dev_ops (9S)
.sp
.LP
\fIWriting Device Drivers\fR
.SH NOTES
Non-\fBgld\fR(4D)-based DLPI network streams drivers are encouraged to switch
to \fBgld\fR(4D). Failing this, a driver that creates DLPI style-2   minor
nodes must specify CLONE_DEV for its style-2 \fBddi_create_minor_node\fR(9F)
nodes and use \fBqassociate\fR(9F). A driver that supports both style-1 and
style-2 minor nodes should return DDI_FAILURE for DDI_INFO_DEVT2INSTANCE and
DDI_INFO_DEVT2DEVINFO \fBgetinfo()\fR calls to style-2 minor nodes. (The
correct association is already established by \fBqassociate\fR(9F)). A driver
that only supports style-2 minor nodes can use \fBddi_no_info\fR(9F) for its
\fBgetinfo()\fR implementation. For drivers that do not follow these rules, the
results of a \fBmodunload\fR(8) of the driver or a \fBcfgadm\fR(8) remove of
hardware controlled by the driver are undefined.
